<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        *{
            margin: 0;
            padding: 0;
            list-style: none;
            text-decoration: none;
        }
        .box{
            width: 500px;
            height: 500px;
            margin: 0 auto;
        }
       
        /* .box div{
            display: none;
        } */
        .men{
            display: none;
            transition: all 3s;
            background: skyblue;
        }
        .box>div{
            display: block;
        }
    </style>
</head>
<body>
    
    <div class="box"></div>
    <script src="./index.js"></script>
</body>
</html>